Add tests for car model

Signed-off-by: Giovanni Baratta <[email protected]>

src/model/car.test.ts

@@ -0,0 +1,155 @@
+import {buildCarExpensesCalculator, CarMonthlyRateAndUpfront, CarMonthlyRateOnly, CarUpfrontOnly} from "./car.ts"
+import {Period} from "./monthly-report.ts"
+import {dateToPeriod} from "../utils/date.ts"
+
+describe("buildCarExpensesCalculator", () => {
+  it("should calculate the monthly report for CarMonthlyRateOnly when the loan is still ongoing", () => {
+    // Given
+    const config: CarMonthlyRateOnly = {
+      type: "CarMonthlyRateOnly",
+      monthlyRate: 100,
+      duration: 12,
+      startDate: new Date(2023, 10, 1)
+    }
+    const calculator = buildCarExpensesCalculator(config)
+    const period: Period = dateToPeriod(new Date(2023, 10, 1))
+
+    // When
+    const monthlyReport = calculator.computeMonthlyReport(period)
+
+    // Then
+    expect(monthlyReport.totalIncome).toBe(0)
+    expect(monthlyReport.period).toEqual(period)
+    expect(monthlyReport.totalExpenses).toBe(100)
+    expect(monthlyReport.detailedExpenses).toEqual({monthlyRate: 100})
+  })
+
+  it("should calculate the monthly report for CarMonthlyRateOnly when the loan is terminated", () => {
+    // Given
+    const config: CarMonthlyRateOnly = {
+      type: "CarMonthlyRateOnly",
+      monthlyRate: 100,
+      duration: 12,
+      startDate: new Date(2023, 10, 1)
+    }
+    const calculator = buildCarExpensesCalculator(config)
+    const period: Period = dateToPeriod(new Date(2024, 10, 1))
+
+    // When
+    const monthlyReport = calculator.computeMonthlyReport(period)
+
+    // Then
+    expect(monthlyReport.totalIncome).toBe(0)
+    expect(monthlyReport.period).toEqual(period)
+    expect(monthlyReport.totalExpenses).toBe(0)
+    expect(monthlyReport.detailedExpenses).toEqual({})
+  })
+
+  it("should calculate monthly report for CarUpfrontOnly when period is the same as the date", () => {
+    // Given
+    const config: CarUpfrontOnly = {
+      type: "CarUpfrontOnly",
+      date: new Date(2023, 10, 10),
+      upfront: 1000
+    }
+    const calculator = buildCarExpensesCalculator(config)
+    const period: Period = dateToPeriod(new Date(2023, 10, 1))
+
+    // When
+    const monthlyReport = calculator.computeMonthlyReport(period)
+
+    // Then
+    expect(monthlyReport.totalIncome).toBe(0)
+    expect(monthlyReport.period).toEqual(period)
+    expect(monthlyReport.totalExpenses).toBe(1000)
+    expect(monthlyReport.detailedExpenses).toEqual({upfront: 1000})
+  })
+
+  it("should calculate monthly report for CarUpfrontOnly when period is not the same as the date", () => {
+    // Given
+    const config: CarUpfrontOnly = {
+      type: "CarUpfrontOnly",
+      date: new Date(2023, 10, 10),
+      upfront: 1000
+    }
+    const calculator = buildCarExpensesCalculator(config)
+    const period: Period = dateToPeriod(new Date(2023, 11, 1))
+
+    // When
+    const monthlyReport = calculator.computeMonthlyReport(period)
+
+    // Then
+    expect(monthlyReport.totalIncome).toBe(0)
+    expect(monthlyReport.period).toEqual(period)
+    expect(monthlyReport.totalExpenses).toBe(0)
+    expect(monthlyReport.detailedExpenses).toEqual({})
+  })
+
+  it("should calculate monthly report for CarMonthlyRateAndUpfront for the first period", () => {
+    // Given
+    const config: CarMonthlyRateAndUpfront = {
+      type: "CarMonthlyRateAndUpfront",
+      monthlyRate: 100,
+      duration: 12,
+      startDate: new Date(2023, 10, 1),
+      upfront: 1000
+    }
+    const calculator = buildCarExpensesCalculator(config)
+    const period: Period = dateToPeriod(new Date(2023, 10, 1))
+
+    // When
+    const monthlyReport = calculator.computeMonthlyReport(period)
+
+    // Then
+    expect(monthlyReport.totalIncome).toBe(0)
+    expect(monthlyReport.period).toEqual(period)
+    expect(monthlyReport.totalExpenses).toBe(1100)
+    expect(monthlyReport.detailedExpenses).toEqual({upfront: 1000, monthlyRate: 100})
+  })
+
+  it("should calculate monthly report for CarMonthlyRateAndUpfront for the "
+    + "subsequents periods when the period is within the loan duration", () => {
+    // Given
+    const config: CarMonthlyRateAndUpfront = {
+      type: "CarMonthlyRateAndUpfront",
+      monthlyRate: 100,
+      duration: 12,
+      startDate: new Date(2023, 10, 1),
+      upfront: 1000
+    }
+    const calculator = buildCarExpensesCalculator(config)
+    const period: Period = dateToPeriod(new Date(2023, 11, 1))
+
+    // When
+    const monthlyReport = calculator.computeMonthlyReport(period)
+
+    // Then
+    expect(monthlyReport.totalIncome).toBe(0)
+    expect(monthlyReport.period).toEqual(period)
+    expect(monthlyReport.totalExpenses).toBe(100)
+    expect(monthlyReport.detailedExpenses).toEqual({monthlyRate: 100})
+  })
+
+  it("should calculate monthly report for CarMonthlyRateAndUpfront when the period is outside the loan duration", () => {
+    // Given
+    const config: CarMonthlyRateAndUpfront = {
+      type: "CarMonthlyRateAndUpfront",
+      monthlyRate: 100,
+      duration: 12,
+      startDate: new Date(2023, 10, 1),
+      upfront: 1000
+    }
+    const calculator = buildCarExpensesCalculator(config)
+    const period: Period = dateToPeriod(new Date(2024, 10, 1))
+
+    // When
+    const monthlyReport = calculator.computeMonthlyReport(period)
+
+    // Then
+    expect(monthlyReport.component).toBe("Car")
+    expect(monthlyReport.totalIncome).toBe(0)
+    expect(monthlyReport.period).toEqual(period)
+    expect(monthlyReport.totalExpenses).toBe(0)
+    expect(monthlyReport.detailedExpenses).toEqual({})
+  })
+})

src/model/car.ts

@@ -3,20 +3,20 @@ import {dateToPeriod, getFirstDayOfNextMonthsFrom, isPeriodBetweenStartAndEnd, i
 
 export type CarExpenses = CarMonthlyRateOnly | CarUpfrontOnly | CarMonthlyRateAndUpfront
 
-interface CarMonthlyRateOnly {
+export interface CarMonthlyRateOnly {
   type: "CarMonthlyRateOnly"
   monthlyRate: number
   duration: number
   startDate: Date
 }
 
-interface CarUpfrontOnly {
+export interface CarUpfrontOnly {
   type: "CarUpfrontOnly"
   date: Date
   upfront: number
 }
 
-interface CarMonthlyRateAndUpfront {
+export interface CarMonthlyRateAndUpfront {
   type: "CarMonthlyRateAndUpfront"
   monthlyRate: number
   duration: number